Vinyl polymers plasticized with chlorinated hydrocarbons



Patented July 4, 1950 UNITED STATES PATENT OFFICE VINYL POLYMERSPLASTICIZED WITH CHLORINATED HYDROCARBONS ration No Drawing. ApplicationFebruary 28, 1945, Se-

rial No. 580,274. 1944 12 Claims.

The invention relates to the production of plasticised polyvinylchloride or polyvinyl chloride co-polymers adapted for use for examplein the preparation of coating compositions, cable dielectric compounds,and moulding compositions.

The use of substances of the character of tricresyl phosphate, dibutylphthalate, and dibenzyl sebacate as plasticisers for polyvinyl chlorideor its co-polymers has long been practised. They are polar in character,and are thus known to have an adverse eifect on the electrical and waterresistant properties of the polymers. Their-other physical propertiessuch for example as tensile strength are also known to depreciaterapidly with increasing additions of the plasticisers to thosecompositions.

In a co-pending application Serial No. 513,468, filed August 12, 1943, aprocess is described for producing such compositions in the use asplasticisers or partial plasticisers and/or fillers of certainhydrocarbons obtained from mineral oil fractions by extraction withselective solvents of a polar character. These hydrocarbons arepreferably of molecular weight 250-750 boiling within the range 250-800at 760 mm. Hg pressure. The preferred hydrocarbons are characterised bya high carbon content (at least .6 atom of carbon per atom of hydrogen)and may contain up to two unsaturated linkages per molecule] Thehydrocarbons may alSo contain a minor proportion of sulphur and/ornitrogen in combined form. These high molecular weight hydrocarbons havegood electrical and water resistant properties because of theirnon-polar character, and are compatible with polyvinyl chloride and manypolyvinyl chloride co-polymers, such as the co-polymers of vinylchloride with vinyl acetate, methyl acrylate, vinylidene chloride andthe like, and act as fillers and partial plasticizers in such polymercompositions as are used for moulded and other goods particularly wherea highly plasticised and extensible structure is not desired. I

We have found however that certain extracts are only compatible withpolyvinyl chloride and its co-polymers to a small extent, and thisappears to be the case where the ratio of the extract to the originalhydrocarbon fraction is high, and more particularly where the ratio isgreater than In Great Britain March 1,

z about 25% by weight. We have observed however that this rule does notapply generally to such hydrocarbon fractions derived from all crudemineral oils, and there are certain crude oils from which it is possible'to obtain yields of extracts up to and beyond 25% by weight, whichdisplay satisfactory compatibility with polyvinyl chloride or itsco-polymers.

An object of the invention is to treat such extract hydrocarbons as showpoor compatibility with polyvinyl chloride, whereby not only are theirproperties in this respect greatly improved, but in addition certainother of their properties are also improved, and in particular the lowtemperature flexibility of the resulting polyvinyl chloride andpolyvinyl chloride co-polymer compositions, which is much superior tothat of similar compositions containing untreated extracts. Theinvention is however of general applicationin the treatment of extracthydrocarbons.

According to the invention a mineral oil fraction or residue having thecharacteristics hereinbefore described is first extracted with aselective polar solvent or a mixture of solvents one at least of whichis of a polar character. The desired hydrocarbons are to be found in theextract phase and are recovered by the removal of the solvent,advantageously by distillation. The hydrocarbons thus obtained are thenchlorinated under conditions hereinafter described, and the resultinghydrocarbon material may then be incorporated with polyvinyl chloride orco-polymer compositions as a filler, or as a filler and plasticiser,either alone or with known plasticisers in smaller proportions. Y

The solvent extraction step may be carried out in known manner. We havefound that a mixture of sulphur dioxide and benzene gives satisfactoryresults, but a wide range of other known solvents may advantageously beused for example, sulphur dioxide, alcohols, furfural, and phenols.

The chlorination may be carried out in known manner and advantageouslyby direct bubbling of chlorine through the agitated hydrocarbon materialat a temperature of less than 150 C. and preferably at atmospherictemperature or slightly higher, and at atmospheric pressure. Thechlorination may be carried on until up to of known manner, for example,by distillation, par-.

tial absorption on porous earths or adsorbent material, precipitationwith solvent or otherwise, with theobject of rendering the materiallighter in colourbefore incorporation into compositions as hereinbeforedescribed.

Example 1.-This example illustrates the method of preparation of achlorinated hydrocarbon material. p r

A mineral oil fraction boiling in the approximate range 375-435'C. at760 mm. Hg pressure.

was submitted to multi-stage,- counter-current extraction with amixtureof sulphur dioxide and benzene in the ratio of 85 parts by volumeof sulphur dioxide to 15 parts by volume of benzene, employing a totalproportion of the mixture amounting to 200% by volume of the mineral oilfraction, and a temperature gradient during extraction of 14025 F. Thematerial extracted, after evaporation of the benzol and sulphur dioxide,amounted to 30% by weight of the original mineral oil fraction and had aspecific gravity at 60 F. of 1.00.

The resulting product was treated at approximately room temperature withchlorine by bubbling chlorine throughthe stirred material. No externalcooling was employed. The treatment was continued until the increase inweight due to chlorination amounted to 11% of the weight of the originalhydrocarbon material, and the product at this stage had a specificgravity of 1.026.

Example 2.40 parts by weight of the chlorinated hydrocarbon materialprepared according to Example 1 were mixed at 140 C. in an internalmixer for hr. with 100 parts by weight of polyvinyl chloride, 40 partsby weight 01. dibutyl phthalate and 5 parts by weight of white lead. Theplasticised mass was thereupon moulded under pressure at 150 C. to forma sheet 0.10 inch thick. Aiter'ni'ne months storage at atmospherictemperatures no sweatingof plasticiser was observed, whereas severesweating was observed in a. parallel composition containing theextracted hydrocarbon material, not subjected to chlorination.

'The physical properties determined. on the composition containing thechlorinated material were as indicated in the following Table 1.

Table 1 'lensilestrength 2,200 lb./sq. in. Elongation at Break. 50%Shore Hardness Volume Resistivity Low Temperature Flexibility limit 40C.

67 1.7X" ohms cm.

Example 3.-'I'he following cable insulation compounds containing thechlorinated hydrocarbon material prepared according to Example 1,

were mixed for 20 minutes at 120 C,, in an inter-.

nal mixer, and thenon an open roll mill for 20 minutes at 140 C. Theplasticised sheets thus p. s. :Iamperaturo Flexibility Lim- I Table 2Compound No l 2 p 3 Polyvinyl chloride 100 100 "10"- H drocarbonmaterial 25 C orinated hydrocarbon material- 25 Dlbutyl phtlialate" 2525 30 Lead sillcate.- 4 4 4 Ethyl palmitate 2 2 2 Properties TensileStrength, lb.lsq. 111-1 2, 920 3, 223 2, 823

Elongation at break, per cent. 210 27 Shore Hardness 80 75 VolumeResistivity, ohm cm. 5X10 3X10 1X10" Specific Inductive Capacity:

a eas a; Loss Factor:

50 c. p. s 0. 102 0. 105 0. 100

We claim: 1. A process for the production of vinyl polymer plasticcompositions of improved low temperature flexibility and improvedelectrical properties comprising intimately incorporating at amoderately elevated temperature a vinyl polymer asv specified in claim 1in which the chlorination polyvinyl chloride, vinyl chloride-vinylacetate co-polymer, vinyl chloride-methyl acrylate co- -polymer, andvinyl chloride-vinylidene chloride co-polymer, with chlorinatedhydrocarbons which have'been produced by extracting frommineral oilfractions hydrocarbons of molecular weight in the range 200-800, havinginitial and final boiling points within the range 250-800 C. at 760 mm.of mercury pressure, containing up to two unsaturated linkages permolecule and having a carbon content of on average at least 0.6 atom ofcarbon per atom of hydrogen, said hydrocarbons being extracted with asolvent substance of polar character which forms an extract phase withthe said hydrocarbons, removing said solvent substance from said phaseto recover said hydrocarbons as an extract material and chlorinating thesaid hydrocarbons at about atmospheric temperature and about atmosphericpressure until up to 50% by weight of chlorine has been taken up, basedon the weight of the said hydrocarbons. g

2. A process for producing plastic compositions as specified in claim 1in which the chlorinated hydrocarbons have been produced by directbubbling of chlorine through the extract hydrocarbons while the extracthydrocarbons are in a state of motion. 7

3. A process for producing plastic compositions as specified in claim 1in which the chlorination is carried out until 5-25% of chlorine byweight, I

based upon the extracted hydrocarbons, is taken 4. A process forproducing plastic compositions is carried out until 5-15% of chlorine byweight, based upon the extracted hydrocarbons, is taken 5. A process forproducing plastic compositions as specified in claim 1 in which thechlorination is carried out by direct bubbling of chlorine through theextracted hydrocarbons, maintained in a state of motion, until 5-15% ofchlorine by weight, based upon the extracted hydrocarbons,

weight of the extracted hydrocarbons is in the range of 250-750.

7. A process for producing plastic compositions as specified in claim 1in which the chlorinated hydrocarbons are distilled to render themlighter in colour before admixture with the polyvinyl chloride.

8. A process for producing plastic composition! as specified in claim 1in which the chlorinated hydrocarbons are rendered lighter in colour bypartial adsorption on adsorbent material before admixturewith thepolyvinyl chloride.

9. A composition of matter of improved low temperature flexibility andimproved electrical properties comprising an intimate admixture of avinyl polymer substance selected from the group consisting of polyvinylchloride, vinyl chloridevinyl acetate co-polymer, vinyl chloride-methylacrylate co-polymer, and vinyl chloride-vinylidene chloride co-polymer,with chlorinated hydrocarbons which have been produced by extractingfrom mineral oil fractions hydrocarbons molecular weight in the range200-800, having initial and final boiling points within the range250-000 C. at 760 mm. of mercury pressure, containing up to twounsaturated linkages per molecule and having a carbon content of onaverage at least 0.6 atom of carbon per atom of hydrogen, saidhydrocarbons being extracted with a solvent substance of polar characterwhich forms an extract phase with the said hydrocarbons, removing saidsolvent substance from said phase to recover said hydrocarbons as anextract material and chlorinating the said hydrocarbons at about 8atmospheric temperature and about atmospheric pressure until up to byweight of chlorine has been taken up, based on the weight of the saidhydrocarbons 10. A composition of matter as specified in claim 9 inwhich the chlorination is carried out until 545% of chlorine by weight,based upon the extracted hydrocarbons, is taken up.

11. A composition of matter as specified in claim I in which thechlorinated hydrocarbons are. distilled to render them lighter in colourbefore admixture with the vinyl polymer substance.

12. A composition of matter as specified in claim 9 in which thechlorinated hydrocarbons are rendered lighter in colour by partialadsorption on adsorbent material before admixture with the vinyl polymersubstance.

ERIC WILLIAM MUS'I'HER FAWCETT. ERIC BYLVEBTER NARRACO'IT.

REFERENCES CITED The iollowing references are of record in the.

file 01 this patent:

UNITED STATES PATENTS Number Name Date 2,365,053 Churchill et al. Dec.l2, 19

OTHER REFERENCES Vinylite Co-polymer Resins for Surface Coatingl. page27. published by Carbide I: Carbon chemicals Corporation, 1942.

1. A PROCESS FOR THE PRODUCTION OF VINYL POLYMER PLASTIC COMPOSITIONS OFIMPROVED LOW TEMPERATURE FLEXIBILITY AND IMPROVED ELECTRICAL PROPERTIESCOMPRISING INTIMATELY INCORPORATING AT A MODERATELY ELEVATED TEMPERATUREA VINYL POLYMER SUBSTANCE SELECTED FROM THE GROUP CONSISTING OFPOLYVINYL CHLORIDE, VINYL CHLORIDE-VINYL ACETATE CO-POLYMER, VINYLCHLORIDE-METHYL ACRYLATE COPOLYMER, AND VINYL CHLORIDE-VINYLIDENECHLORIDE CO-POLYMER, WITH CHLORINATED HYDORCARBONS WHICH HAVE BEENPRODUCED BY EXTRACTING FROM MINERAL OIL FRACTIONS HYDROCARBONS OFMOLECULAR WEIGHT IN THE RANGE 200-800, HAVING INITIAL AND FINAL BOILINGPOINTS WITHIN THE RANGE 250-800*C. AT 760 MM. OF MERCURY PRESSURE,CONTAINING UP TO TWO UNSATURATED LINKAGES PER MOLECULE AND HAVING ACARBON CONTENT OF ON AVERAGE AT LEAST 0.6 ATOM OF CARBON PER ATOM OFHYDROGEN, SAID HYDROCARBONS BEING EXTRACTED WITH A SOLVENT SUBSTANCE OFPOLAR CHARACTER WHICH FORMS AN EXTRACT PHASE WITH THE SAID HYDROCARBONS,REMOVING SAID SOLVENT SUBSTANCE FROM SAID PHASE TO RECOVER SAIDHYDROCARBONS AS AN EXTRACT MATERIAL AND CHLORINATING THE SAIDHYDROCARBONS AT ABOUT ATMOSPHERIC TEMPERATURE AND ABOUT ATMOSPHERICPRESSURE UNTIL UP TO 50% BY WEIGHT OF CHLORINE HAS BEEN TAKEN UP, BASEDON THE WEIGHT OF THE SAID HYDROCARBONS.